<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Invisible pain that I dared to inflict to You – [Undertale AU – Nightmare x Killer] by Nymphiou</title>
<style type="text/css">

body { background-color: #ffffff; }
.CI {
text-align:center;
margin-top:0px;
margin-bottom:0px;
padding:0px;
}
.center   {text-align: center;}
.cover    {text-align: center;}
.full     {width: 100%; }
.quarter  {width: 25%; }
.smcap    {font-variant: small-caps;}
.u        {text-decoration: underline;}
.bold     {font-weight: bold;}
</style>
</head>
<body>
<h1><a href="https://archiveofourown.org/works/25577197">Invisible pain that I dared to inflict to You – [Undertale AU – Nightmare x Killer]</a> by <a class='authorlink' href='https://archiveofourown.org/users/Nymphiou/pseuds/Nymphiou'>Nymphiou</a></h1>

<table class="full">

<tr><td><b>Category:</b></td><td>Undertale (Video Game)</td></tr>

<tr><td><b>Genre:</b></td><td>..okay maybe a little, Angst, Angst and Feels, Angst and Smut, Consensual Non-Consent, Happy or Bad ending ? You made your own choice., M/M, Rape/Non-con Elements, Smut, Surprise Ending, The man can't understand people, he's just fucking dumb, mid consentual, nootmare the stupid, seriously i ship them too much</td></tr>

<tr><td><b>Language:</b></td><td>English</td></tr>

<tr><td><b>Status:</b></td><td>Completed</td></tr>

<tr><td><b>Published:</b></td><td>2020-07-28</td></tr>

<tr><td><b>Updated:</b></td><td>2020-07-28</td></tr>

<tr><td><b>Packaged:</b></td><td>2021-05-05 03:21:03</td></tr>

<tr><td><b>Rating:</b></td><td>General Audiences</td></tr>

<tr><td><b>Warnings:</b></td><td>Graphic Depictions Of Violence, Rape/Non-Con</td></tr>

<tr><td><b>Chapters:</b></td><td>1</td></tr>

<tr><td><b>Words:</b></td><td>4,239</td></tr>

<tr><td><b>Publisher:</b></td><td>archiveofourown.org</td></tr>

<tr><td><b>Story URL:</b></td><td>https://archiveofourown.org/works/25577197</td></tr>

<tr><td><b>Author URL:</b></td><td>https://archiveofourown.org/users/Nymphiou/pseuds/Nymphiou</td></tr>

<tr><td><b>Summary:</b></td><td><div class="userstuff">
              <p>When did it get out of hand? </p><p>He wasn't even counting the days, to tell you the truth.<br/>He would have liked to do something...</p><p>But when love gets stronger...</p><p>Getting over and over again was better than being ignored like it used to be.<br/>Even if it would bring him to his end.</p><p>But it will end well, won't it...?</p><p>Yes... everything will end well.</p>
            </div></td></tr>

<tr><td><b>Relationships:</b></td><td>Killermare, NightKiller, Nightkill - Relationship, Nightmare/Killer, Nightmare/Killer Sans</td></tr>

<tr><td><b>Comments:</b></td><td>2</td></tr>

<tr><td><b>Kudos:</b></td><td>38</td></tr>

</table>

<a name="section0001"><h2>Invisible pain that I dared to inflict to You – [Undertale AU – Nightmare x Killer]</h2></a>
<div class="story"><div class="fff_chapter_notes fff_head_notes"><b>Author's Note:</b><blockquote class="userstuff">
      <p>*****</p><p>Ship: Nightkiller (Nightmare x Killer)</p><p>Lemon: Yes.</p><p>Current status: Skeletons. Presence of magic.</p><p>Sphere/Universe/Place : Dreamtale, Castle of the Master of Doom.</p><p>Main characters:</p><p>- Nightmare, and therefore Dreamtale btw, belong to Jokublog.<br/>- Killer belongs to Rahafawbas.</p><p>Secondary characters :</p><p>- Dust belongs to Ask-Dusttale.<br/>- Horror belongs to Sour-apple-studios.<br/>- Science belongs to Talkingsoup.</p><p>Sorry for the lil mistakes, i do my best :')</p><p>Enjoy and hope you like it !</p><p>*****</p>
    </blockquote></div><div class="userstuff module">
    
    <p>It's not my fault.</p><p>I'm not to blame…</p><p>It's not my fault. It's not my... </p><p>"It's my fault...”</p><p>A sob broke the silence of this room empty of light, as Killer cowered over himself, passing his arms around his legs, his skull resting against his knees in order to warm himself as he could, now naked and soaked in wet water, completely bone-dry in a corner of his room in the castle, having no courage to move, to get up and dry off, to change his clothes or even take a plaid or a blanket...nothing.</p><p>"It's all my fucking fault." he squealed in a voice that had become hoarse, hoarse and tired from crying too many times, shouting too many times…</p><p>It was all his fault.</p><p>He couldn't take it anymore...he was exhausted.<br/>
And it was all his fault... his fault too…</p><p>He was going crazy...even crazier than he was before…</p><p>"Killer! " shouted a loud and hurried voice from one of his friends and mission partners. Dust. "The Boss sent me.” He barely held another sob to his throat as he stared blankly at the door, the psychopath on the other side. "We've got to get to his office.”</p><p>He heard a few footsteps being taken, showing that he was going to leave, but this had immediately stopped, letting him hear an expletive in the company of one of the famous and well known "Tch." by Dust. "You'd better hurry up, he's in a killing mood.”</p><p>A few more seconds passed after his final departure as Killer vainly got up from the floor, his heavy and painful body, covered with scars that were beginning to become far too present and painful, being far too bad at healing magic. He grabbed his jacket and put it on without a word before closing it, while putting on his white shorts in a magic trick, without putting on anything else but this, for lack of strength. And then anyway...he didn't really want to.<br/>
Coming out of his room with slow steps at first, the killer with his soul outside his rib cage had nevertheless to speed up the pace despite the throbbing pain he had endured and endured for a long time. Far too long.<br/>
And finally, when he had arrived, in front of that wooden door dark as the blackness of darkness, a reddish breath of magic rose from his body, coming to wrap itself around him like a gust of wind, aiming to erase with a single blow all his wounds and scars, all his bones that were cracked, becoming as good as new and in good condition, just like his tired features under his orbits that were only hidden by illusion now. It was Killer, the Resets killer, the skeleton with the soul of Determination, the smiling and sadistic sentimental soul that was now to be found again. No one else.<br/>
At the end, he took his courage in both hands before raising one of his ivory hands and knocking four times as he had learned, waiting for permission to enter before lowering the latch of that door of misery and entering the sacred place that was his superior's office. And oh, how he wanted to run for his life, right there, right away. Nightmare's look at him was dark, frightening, frightening...he was used to it though, since the time he's been at his orders.... But when it is different...he was like a vulgar rabbit, facing the big and bad wolf who wanted to devour him raw, with strength and grip, as if he was starving.</p><p>"Here you are at last. "...had made the Master of Misfortune with a sweet, honeyed voice... too much for it to be normal and healthy. "We can begin...~ " </p><p>And when the corrupted fist fell on the smooth oak desk, the three henchmen found here could not help but shudder, even though each one knew they were about to get the soap.<br/>
A broken arm, broken bones, cracked ribs...Horror and Dust had not exactly come out of this confrontation unscathed. Only Killer had suffered the least, simply hitting the wall with a force that was meant to be controlled by the Master of Misfortune...it was normal after all.</p><p>"Get out of here and don't let me see you again until your next assignment! " he growled at this one before he began to stare at the killer's target soul. "And you... " he pointed at him before he pointed at the ground. "You stay here, though</p><p>Killer, as if he found it absolutely normal, only nodded his head as a positive sign, feeling the sorry looks of his friends and associates behind him as they closed the big door behind them, thinking he was going to get a good float.<br/>
...But he didn't.</p><p>"I need to clear my head. " he suddenly let go and stared at his subordinate. "Take off your clothes and come here."</p><p>Nightmare didn't even need to repeat himself a second time to tell the truth, Killer already obeying only the first words said as by simple automatism, opening the zipper of his jacket and taking it off, revealing his rib cage to the dark and envious look of the Master of Misfortunes, as was his pelvis after his shorts were lowered at his feet, before he started walking to one side of the desk and knelt down, his face turned to the obscene view of Nightmare's pelvis, which had already lowered his shorts, revealing a blue limb already well erected and ready. Was he having as much effect on her as that?<br/>
And as Killer was about to raise his skull towards him to ask his permission, he unfortunately didn't need it, suddenly feeling the phalanges of the dark one who opened his jaws and his mouth cavity by force in large as he felt the member of this one inviting himself to it with a straight and sharp blow, hitting directly at the bottom of his throat, which made him squeak and choke with surprise but also with fear, literally not expecting it. Especially when he found himself with his breath cut off. He could hardly breathe...And it didn't get any better, feeling the tentacles of the corrupted man against his spine, his neck and also the contour of his pelvis, totally preventing him from moving or removing what he was holding in his mouth.<br/>
And on top of that was added the hand resting on the back of his skull, directing it with speed from front to back so that he could suck what he had in spite of himself, touching the back of his throat as many times as Nightmare could, simply letting it serve to stay on his knees and wait, his breathing always cut off, letting him little by little see the stars around him of what was unconsciousness, while his torturer grunted with satisfaction without even stopping, paying no attention to what he was doing, thinking only of arriving at the abyss of liberation, not giving a glance at the suffocating killer.<br/>
But what happened, happened, Nightmare, in a last groan, gave a last blow of hip in the large cavity of Killer's mouth, releasing without restraint his semen in the back of his mouth, finally retiring and getting dressed again, still holding a Killer who coughed with force with his sight blurred in his appendages, while he, sketched a big smile, gently approaching his current partner and stooping down towards him, the two faces now at the same level, face to face, before the one with the only pupil takes possession of the teeth of the one with the empty eye sockets, offering him a hugged kiss, long but without any sensation, not even sweetness as opposed to the satisfaction that was omnipresent. .<br/>
This had, in spite of everything, the gift of adorning a red tint to the cheekbones of the skeleton always maintained, while he displayed a blissful air. He had never done that to him... even less after such a contact in his company, with him, his henchman... Did he feel sorry after having been so rough and dry with him just before?<br/>
The killer of thousands of Resets was wondering, at the time…</p><p>And question to ask, this one was going to take the floor in order to ask for an answer, brief as it may be, but was quickly cut clean, his words melting in the exclamation which he had just emitted, at the limit of the acute cry while feeling one of the appendices entering in him with speed in his straitjacket which had just appeared by force, making him shiver by the cold of this corruption while arching his spine in spite of his position my disturbing faith. The tentacle was simply moving in all directions inside him, the tip of it intentionally or unintentionally scratching his magical walls before touching his prostate, making him whine with pleasure and great pain despite his hoarse voice, all this before his superior who stared at him with his dark azure and satisfied look, simply continuing to give good time, even if he was intentionally giving her pain, contenting himself with admiring her from his critical pupil, passing his tongue over the edge of his teeth, while the person concerned with all this was gradually reaching the abyss of enjoyment as the seconds went by.<br/>
But while the killer felt he had reached his paroxysm in spite of himself, it was that in the end, all of a sudden, Nightmare had totally stopped his appendages, making Killer whine with frustration and surprise until he squealed with tears in his eyes as he felt the appendages withdraw from him and his body, letting him fall back to the ground, frustrated and on the verge of mental breakdown, at the crisis of tears so much he suffered...<br/>
It wasn't the first time he'd done this to him and yet...he satisfied him well, he did...<br/>
And despite everything, a few seconds after the corrupted man's words to make him leave, it was a trembling Killer who teleported himself into his room and dropped to the ground while squealing in pain as he felt his pelvis and his magic still active coming against the cold slab floor. More cuts, and inside his magic straitjacket this time... Still trying to get up, not without pain, he ends up going to the bathroom adjacent to his bedroom, putting his clothes in his laundry tub and venturing into the huge black marble shower he had, putting himself under the hanging shower head and throwing the water...cold. He let his magic evaporate around his body, letting his wounds, including his current ones, show up again...he had incredible pain in his mouth cavity by the way, his words becoming painful at the slightest speech, so he should avoid speaking until he was better, at least a little...he didn't want to arouse suspicion towards his friends or Nightmare himself, possibly making it worse from the very beginning.</p><p>Yes, Nightmare was a real sadist, and he knew it despite his little masochistic side that he had...But despite everything...he loved him. He loved him, even if it meant suffering, even if it meant hurting himself morally or physically...even if it meant giving his life.<br/>
Yes, Killer was simply in love. Crazy and addicted to the corrupt, despite his constant suffering...</p><p>He remembers it well, the day when, after having dared to confess to his superior and sweet nightmare prince that he loved him, the latter had teleported them to his room to make him scream with pleasure all night long, until dawn...Coming out with simple superficial wounds, including his coccyx which was the worst, having had a hard time walking during the day.<br/>
But...it was only the one and only time that Killer felt loved, appreciated by his gentle and horrible torturer.<br/>
In spite of the time that had passed, which was already...about six years ago, Nightmare had never granted him a single sweetness, either in their nights or days when they were one, to simple hugs, from sweet and warm kisses to a simple "I love you"...Today had been different though, the corrupted one having offered him a kiss for sure, but...He was not satisfied with it.<br/>
That kiss was neutral. So neutral... it didn't really matter... A real kiss was supposed to show the other person how you felt, to show how much you liked him or that you loved him...<br/>
Killer couldn't help but burst into tears under the icy water in her shower thinking about it, letting herself fall to her knees on the floor, hands trying to stop those damn tears that expressed everything he wasn't saying loud and clear, always keeping everything to herself. Why did he...? Just, why?<br/>
Why did it have to fall on him? Why couldn't he be loved? Why did Nightmare play with his feelings like that? Why did he get his hopes up? To suffer more and more... ?</p><p>..He didn't even have answers to his own questions. And he might never find them.</p><p>And that lasted, long, too long even ... Time had been treacherous for him, again and again, enduring Nightmare's gentle torture, going back to his room covered with more and more wounds, more and more exhausted, receiving no attention, no loving words, no loving embrace...Nothing.</p><p>Just nothing.</p><p>And inevitably... there were consequences.</p><p>In the imposing library of the castle where two people were now, Nightmare began to growl as he began to come and go to this shimmering red magic that formed inside Killer, which seemed so warm and tight to him for his greatest pleasure to take his current lover in this way, as he is doing right now, the killer finding his ribcage against the ivory-coloured table, his feet touching the ground by the point, his coccyx, finding himself in the void in the air, facing Nightmare who pounded him with all his envy and endurance by his kidney strokes, paying no attention to his appendages which cracked the bones of the one with the targeted soul by holding him ever stronger as the seconds went by. The pleasure he felt in his company was so...so strong, so irresistible. How could Killer, his simple henchman, make such an impression on him?<br/>
He didn't know, or he didn't know the truth as well as he could.<br/>
At first, after the empty-eyed skeleton confessed his feelings for him, he had and saw it as... a game, an occupation, a distraction, a hobby that he could enjoy at his leisure, taking advantage of it, as much as he wanted. He had fun getting his foot in the door, unleashing himself and emptying his mind in their activities, taking advantage of them to play on his sadistic side, frustrating him, making him whine, scream, cry...hurting him a few times in the process...</p><p>But he didn't refuse, always smiled, always accepted, always took care of himself, so... he could always start again, couldn't he?</p><p>Arriving towards his limits, those of the end of his act, Nightmare is preoccupied with giving his last blows, aiming right in the prostate of his partner, making him squeak while the one who got so much good out of killing him didn't notice Killer's hands letting go of his grip on the table he had inked his phalanxes until he hurt himself, not noticing his orbits closing, not noticing that his body didn't move anymore...<br/>
In a last groan of pleasure, Nightmare released his juicy seed in quantity in his magic, letting him catch his breath with a rhythm taken by him, before he withdraws and puts his appendages back in their right place, behind his back... And that he sees Killer's body fall to the ground, without any softness, in a deafening crash accompanied by the breaking of the bones broken during this umpteenth common act, calling out to the incarnation of Negativity who crouched down at his side after a magic trick which aimed at putting him back his clothes on.</p><p>"I was so strong for you this time that you finally fainted, hmm ?~" he purred, running his tongue over his teeth, as he had done far too many times since he and the Resets killer had had this sudden closeness.</p><p>He would have liked to let out an amused, even mocking laughter, but the skull of the vanished skeleton called out to him, as did his bones, which had a different hue, turning to a white different from the usual, almost sickly color...Was he sick?<br/>
His question was quickly answered as he saw Killer's magical parts vanish, disappear, just like his whole magic that was far too flat, just like a certain spell that covered his whole body, by the way... This body which, in its real form, made the nightmare hiccup as a horrible wave of disgust came over him, almost making him vomit if he hadn't held back in time. The skeletal body in front of him was...a ruin. It was at once sad, horrifying, disgusting, nauseous... Wounds all over him, all dating from different dates, times and times, as the news added to this sickening record. Especially when, all this had been caused by Him...by all those moments they had between them, in all those moments when the corrupt thought he was healing himself whenever He could have hurt him... </p><p>He had been blind all this time, blind to see what the killer was hiding, blind to see that the love he wanted simply made him suffer... He had been an idiot, an idiot for hurting him so much, an idiot for not noticing all this, an idiot for taking advantage of him so much...an idiot when in reality he felt the same way he did...not daring to say anything, out of pride in his credibility as leader of the Bad Sans, out of fear of his own feelings, of the love he felt...</p><p>And now there he was, in front of this body that we couldn't even define as beautiful and skeletal, in front of this unconscious body, in front of...in front of everything he dared to do to him...</p><p>He...no...<br/>
...it was all HIS fault.</p><p>His body decided to act before his mind, gently taking the mistreated body in his arms, surrounded by his appendages to protect it from what was left, while he activated his magic in order to teleport himself in less than a second, appearing before a certain scientist who jumped out of stupor as he prepared to preach to the one who had dared to interrupt his experiment... before seeing the dilapidated body of the unconscious skeleton, making him open his pupils before giving the order to put him on the examination table, leaving to look for something to cure Killer, all this in front of an anxious Nightmare, who could do nothing... strictly nothing to do but watch, observe every action Science did, every reaction he had to every observation, every treatment... every possible mimicry, from the frowning of his arches, to the mumbling, to his glasses that he often wore up, to the sweat on his skull that he often wiped with a towel...</p><p>"I don't know if it will be enough." The scientist made him serious after several hours of care, staring at the prince who had just found his feet on the ground. He hadn't even seen the time go by... as long as he was worried... "But it might take some time, so he'll stay here in the meantime. “</p><p>Time.<br/>
Fucking. Time. </p><p>Nightmare didn't even bother to listen to the rest of the words of the skeleton in the white coat that he suddenly disappeared, reappearing in his apartments, in his room, sitting in his bed, his eye empty of life, his body frozen.<br/>
He had become a veritable statue, no longer reacting to the coming of his henchmen who had been told about him, to every meal tray that Horror brought him every morning and evening, to every report of Dust who informed him of Killer's condition... all this as the days went by, without the corrupt doing anything at all, barely working in the dream world to preserve the balance, barely feeding himself so as not to starve to death. It was as if he had lost all life, all spirit...everything, absolutely everything. He was so angry at himself, he was so fucking angry, he was so fucking angry at himself...and it all went from a few days at first to a week...and then a second halfway through...<br/>
Until an end came to him.</p><p>"Nightmare...? " had made a voice, a soft and calm voice, a voice so familiar to him, a voice he hadn't heard for far too long... a voice he had missed so much....</p><p>The person concerned froze. He couldn't believe it...No..no, no, it wasn't him who had just called him. It wasn't his voice. Not his magic that he felt coming closer and closer to him. It wasn't his little arms that rolled around his waist, not even those ivory hands he saw from his one pupil...<br/>
No...it wasn't him...it wasn't real...was it?</p><p>"Nightmare...”</p><p>He felt like he was dreaming...</p><p>"If...if you knew how much I feel sorry for myself... " shivered the corrupt in spite of himself, as the embrace that formed from the barely recovered skeleton tightened. "I..- </p><p>- I screwed up just as badly as you did, you know... I..I should have told you." Nightmare turned around so that he could see the one with the empty orbits, covered with a few bandages and a little tired look on his face, making him feel more and more guilty when he saw him as such.</p><p>The negative couldn't help touching his cheekbone attentively, putting his hand on it, as if he was afraid it would break on contact with him like a porcelain doll...before, finally, the killer pressed his face on him, while a sweet smile adorned all this...a sweet, loving smile...all that he had never done, nor given...</p><p>"I should've...also.." he blew with sorrow, as they both fell into the bed, still intertwined, their legs blending together now, while a blanket was there to cover them, all this before the gaze of Dust and Horror at the door who decided to slip away, to leave them alone.</p><p>"What should you have... ? "Killer gently buried his skull against the rib cage of the one he loved, raising his head slightly to scrutinize his beloved's gaze, from which a small tear had flowed in spite of himself, no longer being able to hold it back. "Oh, Nightmare...</p><p>- I should have told you that I...that i love you too... I should have shown you how I feel, I should have been good to you, and.."He sniffed slowly before burying his face in his neck. "and not to do this to you...”</p><p>In their small and intimate embrace, Nightmare could feel Killer shiver after his words, before, slowly over the seconds, he could hear him gently hiccup, then burst into tears... Had he said something wrong?<br/>
Not when he felt the killer move his head backwards so that they could look at each other, before, with a frail and mitigated movement, the one with the empty eye sockets came to take hostage the teeth of the one with the appendages, in a long and awkward kiss, which said a lot about everything that had happened, which said far too much about his feelings and sentiments, while the corrupted one returned it with a certain timidity, just like the love he was showing him, not without a certain form of fear. </p><p>"I've been waiting for this for so long... "slowly blew the ivory skeleton after their embrace, smiling slowly as the dark-boned one did the same.</p><p>"I'm sorry, Killer..</p><p>- It's all right...it’s nothing..”</p><p>No... it wasn't nothing. They both knew it.</p><p>Yet...they had wanted to forget those moments, those moments when both of them were suffering silently without the other knowing it...acting in the shadows, hiding their pain without even saying so, without even daring to step forward or simply expressing themselves...</p><p>But at the same time... could you blame them? For not facing up to it? For not daring to confront their fears? The fear of their feelings? Fear of abandonment? Fear of being pulled away if they said anything?</p><p>No one knew. And clearly, we'll never know.<br/>
Because after all... everything was back to normal, wasn't it...?</p><p>"He still wouldn't have been able to hold it with all that time.." he had heard.</p><p>Unless...</p><p>"Time has been treacherous." he had listened.</p><p>...nothing was true, or even good, deep down...</p><p>"It was all just a nightmare..?" made a skeleton lying in his sheets, staring at the ceiling with no real purpose, thinking again and again of what he had just seen.</p><p>Especially since it was only a stupid dream...</p><p>But...was it a commonplace illusion, or an old memory, that came to mind?<br/>
Only those concerned kept that in mind by playing the king of silence.<br/>
Then no one knew. No one knew.</p><p>And no one will know, after all.</p>
  </div></div>
</body>
</html>